CsPb Br is a ternary halogen-plumbate material with close characteristics to the well-reported halide perovskites. Owing to its unconventional two-dimensional structure, CsPb Br is being looked at broadly for potential applications in optoelectronics. CsPb Br investigations are currently limited to nanostructures and powder forms of the material, which present unclear and conflicting optical properties. In this study, we present the synthesis and characterization of CsPb Br bulk single crystals, which enabled us to finally clarify the material's optical features. Our CsPb Br crystal has a two-dimensional structure with Pb Br layers spaced by Cs cations, and exhibits approximately 3.1 eV indirect band gap with no emission in the visible spectrum.

Here, we demonstrate an approach to synthesizing and structurally characterizing three atomically precise anion-templated silver thiolate nanoclusters, two of which form one-and two-dimensional structural frameworks composed of bipyridine-linked nanocluster nodes (referred to as nanocluster-based frameworks, NCFs). We describe the critical role of the chloride (Cl − ) template in controlling the nanocluster's nuclearity with atomic precision and the effect of a single Ag atom difference in the nanocluster's size in controlling the NCF dimensionality, modulating the optical properties, and improving the thermal stability. With atomically precise assembly and size control, nanoclusters could be widely adopted as building blocks for the construction of tunable cluster-based framework materials.

Copper-based nanomaterials have attracted tremendous interest due to their unique properties in the fields of photoluminescence and catalysis. As a result, studies on the correlation between their molecular structure and their properties are of great importance. Copper nanoclusters are a new class of nanomaterials that can provide an atomic-level view of the crystal structure of copper nanoparticles. Herein, a high-nuclearity copper nanocluster with 81 copper atoms, formulated as [Cu81(PhS)46( t BuNH2)10(H)32]3+ (Cu 81 ), was successfully synthesized and fully studied by X-ray crystallography, X-ray photoelectron spectroscopy, hydrogen evolution experiments, electrospray ionization mass spectrometry, nuclear magnetic resonance spectroscopy, and density functional theory calculations. Cu 81 exhibits extraordinary structural characteristics, including (i) three types of novel epitaxial surface-protecting motifs; (ii) an unusual planar Cu17 core; (iii) a hemispherical shell, comprised of a curved surface layer and a planar surface layer; and (iv) two distinct, self-organized arrangements of protective ligands on the curved and planar surfaces. The present study sheds light on structurally unexplored copper nanomaterials and paves the way for the synthesis of high-nuclearity copper nanoclusters.

Metal-halide perovskite materials are highly attractive materials for optoelectronic applications. However, the instability of perovskite materials caused by moisture and heatinduced degradation impairs future prospects of using these materials. Here we employ water to directly transform films of the three-dimensional (3D) perovskite CsPbBr 3 to stable twodimensional (2D) perovskite-related CsPb 2 Br 5. A sequential dissolution-recrystallization process governs this water induced transformation under PbBr 2 rich condition. We find that these postsynthesized 2D perovskite-related material films exhibit excellent stability against humidity and high photoluminescence quantum yield. We believe that our results provide a new synthetic method to generate stable 2D perovskite-related materials that could be applicable for light emitting device applications.

Although core–shell copper metal nanoclusters are important emerging materials for practical applications and fundamental scientific research, their synthesis lags behind that of gold and silver nanoclusters–challenged by copper’s much lower half-cell reduction potential, M­(I)/M(0). To overcome this synthetic hurdle, we introduce a simple reaction strategy, involving the mild reducing agent borane tert-butylamine complex, to produce a core–shell superatom copper nanocluster, [Cu61(StBu)26S6Cl6H14]+ (−StBu; tert-butyl thiolate), which is the largest Cu(0)-containing structurally-solved core–shell copper cluster to-date. The nanocluster exhibits a quasi-elongated triangular gyrobicupola (quasi-J 36, J 36 = Johnson solid) Cu19 core and a shell held together by a novel “18-crown-6” metal-sulfide-like belt. Because of its stability, this cluster displays a single molecular ion peak in mass spectrometry measurements without any cluster fragmentation signalsa first observation of its kind for copper nanoclusters that paves the way for researchers to study nanocluster composition, charge, stability, and reaction mechanisms with atomic precision that only mass spectrometry could afford.

Due to their atomically precise structure, photoluminescent copper nanoclusters (Cu NCs) have emerged as promising materials in both fundamental studies and technological applications, such as bio‐imaging, cell labeling, phototherapy, and photo‐activated catalysis. In this work, a facile strategy is reported for the synthesis of a novel Cu NCs coprotected by thiolate and phosphine ligands, formulated as [Cu15(PPh3)6(PET)13]2+, which exhibits bright emission in the near‐infrared (NIR) region (≈720 nm) and crystallization‐induced emission enhancement (CIEE) phenomenon. Single crystal X‐ray crystallography shows that the NC possesses an extraordinary distorted trigonal antiprismatic Cu6 core and a, unique among metal clusters, “tri‐blade fan”‐like structure. An in‐depth structural investigation of the ligand shell combined with density functional theory calculations reveal that the extended CH···π and π‐π intermolecular ligand interactions significantly restrict the intramolecular rotations and vibrations and, thus, are a major reason for the CIEE phenomena. This study provides a strategy for the controllable synthesis of structurally defined Cu NCs with NIR luminescence, which enables essential insights into the origins of their optical properties.

Precise identification and in-depth understanding of defects in nanomaterials can aid in rationally modulating defect-induced functionalities. However, few studies have explored vacancy defects in ligand-stabilized metal nanoclusters with well-defined structures, owing to the substantial challenge of synthesizing and isolating such defective metal nanoclusters. Herein, a novel defective copper hydride nanocluster, [Cu 36 H 10 (PET) 24 (PPh 3 ) 6 Cl 2 ] (Cu36; PET: phenylethanethiolate; PPh 3 : triphenylphosphine), is successfully synthesized at the gram scale via a simple one-pot reduction method. Structural analysis reveals that Cu36 is a distorted half cubic nanocluster, evolved from the perfect Nichol's half cube. The two surface copper vacancies in Cu36 are found to be the principal imperfections, which result in some structural adjustments, including copper atom reconstruction near the vacancies as well as ligand modifications (e.g., substitution, migration, and exfoliation). Density functional theory calculations imply that the above-mentioned defects have a considerable influence on the electronic structure and properties. The modeling suggests that the formation of defective Cu36 rather than the perfect half cube is driven by the enlargement of the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital of the nanocluster. The structural evolution induced by the surface copper atom vacancies provides atomically precise insights into the defect-induced readjustment of the local structure and introduces new avenues for understanding the chemistry of defects in nanomaterials.

Polyhydrido copper nanoclusters are an emerging class of nanomaterials. Unfortunately, insights into the structural evolution and structure-property relationship of such copper nanoclusters are scant, due to the difficulty of synthesizing and crystallizing nanoclusters with high nuclearity and new morphologies. Here, we report an anisotropic cuboidal polyhydrido copper nanocluster, [Cu23(PhSe)16(Ph3P)8(H)6]‧BF4, with a distorted cuboctahedral Cu13 core stabilized by two square protecting motifs and six hydrides. The cuboidal nanoclusters self-assemble into a quasi-simple cubic packing pattern with perfect face-to-face contact of neighboring nanoclusters and interdigitation of intercluster surface ligands. Atomic-level observations reveal the crucial role that subtle synergies between nanocluster geometry and intercluster noncovalent interactions play in guiding nanocluster self-assembly. In addition, a comparison with previously reported analogous metal nanoclusters points to bulky monodentate phosphine ligands as a potent inducing agent for the formation of rectangular hexahedral nanoclusters. These findings have significant implications for the controllable synthesis of polyhedral nanomaterials and their superstructures.